1. Field
One or more embodiments described herein relate to a battery charge and discharge control system and a battery charge and discharge control method.
2. Description of the Related Art
A mobile device may operate based on power from a rechargeable battery pack.
In order to extend the time of use of the mobile device, the battery pack may be frequently charged. Another approach involves using two battery packs to power one mobile device. The two battery packs may have the same size and chemical properties.
Each battery pack may have a control circuit and a fuel gauge circuit or a microcomputer. The fuel gauge circuit or microprocessor calculate the capacity of the battery pack. However, these circuits increase the price of the battery pack. In addition, two battery packs used for one device may have the same shape, chemical properties, the capacity, and charge voltage or charge current. This increases size and lowers energy efficiency per volume.
Generally, a battery may experience less deterioration when not in use and may experience greater deterioration when in use. In order to slow deterioration, the battery may be used at a low rate rather than a high rate. In a further attempt to slow deterioration, the battery may only be used when in a better state of charge (SOC) state.
When an energy storage system or battery system, including battery packs connected in series or parallel, is charged or discharged, all battery packs connected in parallel operate. Thus, when batteries are in a rest state or are used for a long time in an SOC region in which deterioration characteristics of the batteries are not relatively good, the lifetimes of the batteries may be reduced.